You were shipwrecked on a desert island with a friend. You
both have a set of two lenses. Yours are +2.00D and -8.00D whereas your friend's are +2.00D and +5.00D. To look for help you
each decided to make a telescope with your lenses.

a. What types of telescope can you and your friend make?

b. What are the lengths of the telescopes made by you and that of
your friend?